1. Field of the Disclosure
The disclosure relates to blood treatment systems and methods. More particularly, the disclosure relates to systems and methods for optically detecting or monitoring characteristics of fluid (e.g., the presence of citrate) within a blood processing device.
2. Description of Related Art
Various blood processing systems now make it possible to collect particular blood constituents, instead of whole blood, from a blood source. Typically, in such systems, whole blood is drawn from a blood source, the particular blood component or constituent is separated, removed, and collected, and the remaining blood constituents are returned to the blood source. Removing only particular constituents is particularly advantageous when the blood source is a human donor, because potentially less time is needed for the donor's body to return to pre-donation levels, and donations can be made at more frequent intervals than when whole blood is collected. This increases the overall supply of blood constituents, such as plasma and platelets, made available for transfer and/or therapeutic treatment.
Whole blood may be separated into its constituents through any of a number of automated procedures, such as centrifugation, membrane separation, and others. Centrifugation, for example, requires that the whole blood be passed through a centrifuge after it is withdrawn from, and before it is returned to, the blood source. To reduce contamination and possible infection (if the blood source is a human donor or patient), the blood is preferably processed within a sealed, sterile fluid flow system during the centrifugation process. Typical blood processing systems include a disposable, sealed, and sterile flow circuit, including a centrifuge chamber portion, that is mounted in cooperation on a durable, reusable assembly containing the hardware (centrifuge, drive system, pumps, valve actuators, programmable controller, and the like) that rotates a centrifuge chamber and controls the flow through the fluid circuit.
In some cases, the disposable flow circuit is configured to allow attachment of additional components, such as bags containing fluids used during the procedure. These fluids may be used for different purposes, such as anticoagulant fluid for preventing the coagulation of blood outside of the body, storage fluid to be added to separated blood components for long-term storage, and replacement fluid to be infused into a patient or donor to replace blood components that are being stored for later use. Some fluids that are used for one purpose may be harmful if used for a different purpose. For example, sodium citrate is commonly used as an anticoagulant, but the excess infusion of sodium citrate into a patient or donor may be potentially harmful by overly increasing the citrate concentration of the blood. Accordingly, care must be taken to ensure that the proper fluid containers are connected to the various ports or access points of a disposable flow circuit.